You're probably aware that you're not at your best when you're exhausted, but a new study shows that your decision-making skills are severely impaired simply because you haven't slept. Stimulants don't help. If you haven't slept, you might as well just make a random choice. Dr. Dennis Rosen, writing for Psychology Today, explains:

Researchers at Harvard Medical School and McLean Hospital recently found that people who were sleep deprived performed less well on a standardized test simulating real-life decision making known as the Iowa Gambling Test than they had at baseline when they were well rested. Even when given stimulants such as caffeine or amphetamines, the ability of the participants to make good decisions only returned to baseline after they had recovery sleep.

Before you decide, be sure to sleep on it otherwise you never know where you're going to end up.